To safely deliver fuel in high pressure systems, modern fuel systems include measures to contain fuel leaks that may occur. For example, marine agency requirements such as the International Convention for the Safety of Life at Sea (SOLAS) treaty require double-walled fuel lines to prevent the likelihood of fire on a commercial marine vessel. These double-walled fuel lines must include a gap between the inner and outer walls to allow any fuel leaked from the inner wall to be detected by a fuel sensor while being contained by the outer wall.